The present invention relates to a multiplexed frequency radio linked apparatus. In general terms, it is used in telecommunications and is more specifically used in the construction of phonic communication means between a number of persons remote from one another or who are insulated from one another as a result of wearing tightly sealed suits, which is in particular the case with persons working in a hostile medium and more specifically in enclosures for the decontamination of radioactive materials and objects.
Operators working on such enclosures wear ventilated clothes which entirely insulate them from the ambient medium. These special working conditions make it necessary both for safety reasons, as well as for efficiency and comfort to use communications means between the operators and the persons located within the enclosure.
Under such conditions, apparatus having wires are not generally satisfactory due to the permanent risk of the wires breaking and of the poor quality of the connection.
Therefore, in the prior art, a wire-less connection system by electomagnetic wave has been used. Such a system comprises a number of transceivers, each operator having such a transceiver at his disposal, hereinafter called the operator transceiver, whilst the person located outside the enclosure has another transceiver, hereinafter called the control transceiver. In improved systems, each of the communication channels established between the operator transceiver and the control transceiver can be on a special frequency in order to obviate the interference between messages emanating from different operators. Thus, a frequency multiplexed system is obtained. Naturally, this makes it necessary for the control transceiver to be equipped with the same number of receivers as there are operator transceivers, whereby each of said receivers works on a special frequency. The control transceiver can be equipped with the same number of transmitters as there are operator transceivers, but it is only possible to use a single transmitter, the receivers of the operator transceivers then being all identical.
The disadvantage of such a system is obvious. Although the operators are able to converse with the person controlling the work, positioned outside the decontamination enclosure, they are unable to converse with one another. If it is desired to give the operator such a facility, it is necessary to duplicate the equipment of each operator by adding a transceiver able to establish communications between the individual operators.